Chicago ‘L’ Structure and CTA Sign in the Loop

The Chicago Transit Authority (CTA) logo is displayed beneath the elevated "L" tracks that traverse the Loop, Chicago's central business district. Constructed in the late 19th century, the "L" system is a defining feature of the city's urban landscape and a testament to early public transit engineering. The steel structure, with its original girders and riveted beams, carries trains above streets lined with historic architecture. The CTA continues to operate one of the nation's largest and oldest public transit networks, serving over a million riders daily.